Chest protector in sports medicine

ABSTRACT

A chest protector, in sports medicine, adapted for players of the athletic games, is light in weight and reasonably comfortable to wear. It will protect the heart and chest cavity area of players in such games as lacrosse, field hockey, and baseball. The chest protector includes a shirt, preferably of two-way stretch fabric, having a large front pocket across its chest area. A protector plate is positioned within the pocket. The protector plate is an assembly of molded layers, comprising inner-most and outer-most layers of plastic, preferably polyethylene sheets; a central layer of a high impact polymer pad, preferably a dry polyurethane gel; and two layers of high impact resistant fabric of high tensile strength fibers, preferably para-aramid fibers, with the polymer pad being sandwiched between the two layers of impact resistant fabric.

FIELD OF THE INVENTION

The present invention relates to athletic equipment and moreparticularly to a sports medicine chest protector to protect the chestcavity and heart of players in contact sports, particularly lacrosse.

BACKGROUND OF THE INVENTION

At the present time a number of chest protectors, to protect playersduring athletic games, are widely used. For example, padded chestprotectors are used in baseball, for the catcher, and they are used inlacrosse, field hockey, and in ice hockey for the goal keeper.

However, in many sports, chest protectors are not used because theplayers must run in order to play the game and they do not want to wearheavily padded garments. This is less of a problem in those sports usinglarge or soft balls. In those sports, such as soccer and basketball, theforce of the ball, because it is large, is less likely to cause anydamage to the body. However, in some sports the ball or puck is smalland hard and may be propelled at high speed. For example, in lacrosseand baseball, the ball is both small and hard and may be thrown and orhit at speeds of between seventy and one hundred miles an hour, even inamateur games.

In the past few years a number of injuries and deaths have resulted whenchildren were hit in the chest by a lacrosse ball. A small number ofschools, as a result, have installed automated external defibrillatorsto revive the child who goes into cardiac arrest from commotio cordisbecause of a shock to the chest. This program is limited, due to thecost of such defibrillators and the strong possibility that when theyare needed neither the defibrillator nor someone trained in its usewould be available. A review article, by Doctor Mark Link of the TuftsMedical Center, points out the significant percentage of deaths on theamateur lacrosse field are due to impact to the chest area, causingcommotio cordis (sudden cardiac arrest). This problem is most frequentlyobserved in young athletes, ages 4 to 18. The victims are most oftensuffering from ventricular fibrillation, a fast heartbeat rhythm whichis life threatening. The Sport Science and Safety Committee of the U.S.Lacrosse Association has recently found that there are no chestprotectors on the market, for lacrosse players, which they approved andwhich eliminate the risk of dying from chest injury when struck by alacrosse ball.

The United States patent literature includes various patents andpublished patent applications directed toward chest protectors insports. Many of these are suitable for a baseball catcher who does notrun around a field when catching pitched baseballs. In U.S. Pat. No.6,182,299 to Chen, a baseball chest protector includes a pad body and aseries of shock absorbent pad blocks. In U.S. Pat. No. 6,519,782 toCollins et al., a baseball chest protector includes an ambient airfilled pouch assembly.

Other patents are directed toward chest protectors for the players whonormally run while playing. In U.S. Pat. No. 5,769,688 to Holliday, abra-like chest protector for women athletes comprises a soft foamexterior and a hard, high density plastic internal breast plate. In U.S.Pat. No. 5,325,537 to Marion, an internal breast plate athletic safetyjacket has a circular plate over the heart area.

In U.S. Pat. No. 3,500,472 to Castellania, a sleeveless chest protectorhas pockets holding inflatable cushions. U.S. Pat. No. 4,610,035 toMattila, relates to an upper body protector having semi-rigid chest andshoulder portions. U.S. Pat. No. 5,950,249 to Clemet discloses a chestprotector having a plastic cap-like shaped plate attached to a rubberpad which protrudes from a soft terry cloth pocket. In U.S. Pat. No.5,325,537 to Marioa an athletic jacket has rigid compressed, denseplastic foam pieces and a rigid hard shield over the heart.

SUMMARY OF THE INVENTION

The present invention relates to a light-weight chest protector, insports medicine, which is sufficiently light in weight and comfortableto wear so that it would be willingly worn by children and others whenthey play running sports, such as lacrosse. A chest protector plate fitssnugly in a special large front pocket of a special shirt. The shirt isof a suitable plastic resin fabric, preferably a two way stretch fabric,such as “CyberKnit” (™ of Paul Gottlieb and Co.) The shirt is washableand wicks moisture away from the player's body. For example, the shirt'sfabric may be made from polyester and polypropylene fibers.

The “chest protector” is the combination of the shirt and the chestprotector plate. The shirt and the plate come in a number of sizes, i.e.child, small, medium and large in order to fit various players, with thesize of the protector plate conforming to the size of the shirt.

In one preferred embodiment, the chest protector plate is molded, tocurve like an average chest. The protector plate has inner-most andouter-most layers each of a plastic sheet, preferably low densitypolyethylene. The two plastic sheets are molded together to form an airtight pocket which encloses the other layers of the plate. In order,starting with the out-most layer (with respect to the players chest) theother layers are an impact resistant fabric of high tensile strengthfibers, preferably “Kevlar” (™DuPont); a layer of high impact polymerpad which disperses impact energy throughout the pad, the pad beingpreferably a visoelectric dry polymer, and most preferably a hybridpolyurethane elastomer and a second layer of the impact resistant fabricof high tensile strength fibers. The polymer pad is sandwiched betweenthe two layers of high impact resistant fabric. The five layers arebonded and laminated together to form a unitary thin and lightweightprotector plate.

The chest protector of the present invention is especially useful insome sports, such as lacrosse and baseball. However, it is sufficientlylight and comfortable so that it may be worn to protect players,particularly children, in other sports including soccer, field hockey,softball and touch football.

Although the preferred way to position the chest protector plate is toenclose it within a large front shirt pocket which is across the widthto the shirt, although the ‘shirt’ may be a separate pocket held bystraps on the chest of the player.

BRIEF DESCRIPTION OF THE DRAWING

The following detailed description of the invention should be taken inconjunction with the accompanying drawing. In the drawing:

FIG. 1 is a front plan view of the chest protector plate, partly brokenaway;

FIG. 2 is a top plan view of the chest protector plate;

FIG. 3 is a front plan view of the shirt, partly cut away, showing itsenclosed chest protector plate; and

FIG. 4 is an enlarged side view of a cross section of the chestprotector plate.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, the chest protector plate 10 is large enough tocover the heart and chest cavity area of the average sports player.Preferably the plate 10 is made in various sizes, for example child,small, medium, and large. The plate 10 has a central section 9 andcurved left and curved right side flanges (as seen from the front)respectfully 11 and 12. The plate is taller on the left side than on theright side.

In one prototype, which is a non-limiting example of the presentinvention, the chest protector plate is of a size suitable for a mediumsize player, about 120-160 pounds (adult male). It is 13½ inches (34.3cm) wide (“a” in FIG. 1); its height at the left side (“b” in FIG. 1) is6½ inches (16.5 cm); its height at the right side (“c” in FIG. 1) is 10½inches (26.7 cm); and its total thickness (except at its edges) is ⅜inches (0.95 cm). The corners of the plate are rounded. The curvature ofthe plate 10 is a 2 inches curvature to the chest, and the curved right11 and left flanges have a curvature having a radius of 7 inches (17.8cm). The central section 9, also has a slight curvature which is bowedoutwardly with respect to the chest. The central section 9 is 7 inches(17.8 cm) wide and the left 12(“d” in FIG. 1) and right 13 (“E” inFIG. 1) flanges are each 6¼ inches (15.87 cm) wide.

As shown in FIG. 4, the outer-most layer 20, and the inner-most layer24, are of high impact, low density polyethylene having preferably athickness of 1/16 inch (1.6 cm) and in the range of 1/32 inch to ¼ inch,before they are vacuum formed.

The layers 21 and 23 are of a cross woven, flexible cloth of high impactmaterial. Preferably the cloth is woven of “Kevlar” (™DuPont), for itspara-aramide fiber, although alternatively the cloth may be woven of“Kevlar” (™DuPont) and carbon graphite filaments or only of carbongraphite filaments. “Kevlar” (™DuPont) is said to bepoly-p-phenyleneterephtalamide and the preferred fabric material, is 5oz. per square yard and 0.01 inches (0.25 cm) thick. It is a hightensile strength fiber.

The second layer, 22, is a layer of a flexible, dense, and impactresistant plastic resin material, (high impact polymer padding),preferably ¼ inch thick (6.35 cm) and the range ⅛ to ½ inch, of hybridpolyurethane elastomer dense foam most preferably “Shock Tec” brand,specifically Shock Tec Air 2HD (™Kemmler Products, Mooresville, N.C.).

The layer 22, is sandwiched between the high tensile strength fabriclayers, 21 and 23. Technically, the material of the preferred polymerpad need is not a ‘foam’, but rather a hybrid polyurethane elastomer(visoelectric dry polymer). An alternative polymer pad is high densityfoam of EVA.

In one alternative, not shown in the drawing nor used in the testsdescribed below, the polymer pad, such as a foam layer, may beimpregnated with a plastic resin, semi-liquid gel, preferably a liquidurethane elastomer gel, to increase its resistance to deformation fromprojectile impacts.

Although the shirt may be a simple T-shirt, which may be short-sleevedor sleeveless, it may also be a long-sleeved shirt. The shirt may comein a various colors and sizes and have arm and shoulder pockets to holdadditional protector plates. Alternatively, pocket 2 for the chestprotector plate may be formed of cloth, or other sheet material, andheld on the chest by straps. The term “shirt’ as used herein, means anygarment or device having a pocket, or plate holder which is at leastover the heart, and preferably which is across the entire chest area.

As shown in FIG. 3, the shirt, 1, is a T-shirt with sleeves. The shirt,1, has a pocket, 2, which is formed by a cloth piece being sewn to thefront of shirt, 1 by line of sewing 3 (dotted line). The pocket extendsacross the front chest area of shirt 1. The pocket and its enclosedprotector plate, cover the heart and chest cavity of the player. Asshown in FIG. 2, the protector plate 10 central section, 9, is slightlybowed outward and its left and right side proportions (flaps), 11 and12, are curved to fit an average player.

The prototype of the protector plate used in the below described testswas formed by laminating the layers within an envelope of heated plasticand shaped in a vacuum forming mold. However, other manufacturingmethods may be used.

The tests were conducted by projecting a small hard ball at a dummy andmeasuring the impact results on the dummy with, and without, thechest-protector plate. The dummy was not a crash test dummy, as used inthe automobile manufacturing industry, but simply a thickness i.e. 57.1mm thick, of homogenous, dense clay on a support.

The first test involved an official hard baseball and a pitching machinewhich threw the ball at a speed of about 62 miles per hour, from adistance of 22 feet, at the target dummy. The average depth ofpenetration (how deep a hole the ball made in the clay dummy) was 35.3mm without the protector plate, and 6 mm with the protector plate. At adistance of 10 feet, under the same conditions, the average depth ofpenetration, without the protective plate was 40.3 mm. With theprotective plate, the average depth of penetration was 6.5 mm. In boththese series of tests, the protector plate reduced the depth ofpenetration by more than 80 percent.

The third test used a 3 ounce street hockey ball, which is the same sizeas a lacrosse ball. It was mounted on the end of a shaft and the shaftwas projected using an accurate long bow (40 lbs.) having a muzzlevelocity of 153 fps. The target (same size clay dummy) was set at 10feet from the ball's initial position. Sixty samples were run (30unprotected, 30 protected). The ball was projected at 103 miles per hour(based on muzzle velocity). The average depth of penetration for theunprotected clay dummy was 27.6 mm and the average depth was 4.95 mm forthe dummy with the protective plate. This was an 83.8 percent reductionin the shock effect.

Although the theory of operation is not necessary to practice thepresent invention, the following is presented as informed speculation:

The outer layer (away from the chest) of the woven impact resistant“Kevlar” (™DuPont) prevents the mass of the projectile ball or puck frompenetration through to the player's chest. The polymer pad (polyurethaneelastomer gel) has excellent shock dispersment properties and greatlyreduces the shock from the projector. The back inner layer of wovenimpact resistant material provides a safety measure against theprojectile completely penetrating the projector plate. The outer-mostand inner-most sheets of plastic form an air tight pocket which trapsair as a cushion pillow to blunt the effect of the forward edge of theprojectile.

The term “high tensile strength fiber” means the maximum tensile stress(nominal) sustained the fiber filaments during a tension test and is atleast 3.0 Gpa.

The preferred material is “Kevlar 49” [para-aramid fibers] (™DuPont)having a density of 1.44 g, 1 cm; tensile modules of 131 Gpa; tensilestrength of 3.6-4.1 Gpa and tensile elongation of 2.8 percent. The term“high impact resistant polymer padding” means high impact resistantdense polymer foams with a density of at least 10 lbs/in³) andvisoelectric dry elastomers. The term “gel” does not refer, when usedwith the term visoelectric dry polymer, to a flowable liquid, butrather, to a dense, dry foam-like sheet.

When a projectile hits the high impact resistant polymer pad, its forceis spread out and dissipated throughout the entire layer of the polymerpad. The polymer pad is defined as being, preferably, a pad that willnot compress more than 70 percent of its original thickness at the pointof impact regardless of the force of impact.

1. A chest protector in sports medicine to protect a player againstinjury from high speed projectiles, such as balls or pucks, comprising:a shirt adapted to be worn by the player with the shirt having a frontchest area, a pocket formed on the shirt and extending sufficientlyacross the width of the shirt front area to cover the heart of theplayer, a chest protector plate within the pocket; the chest protectorplate being an assembly of the following layers; a layer of penetrationresistant woven fabric of high tensile strength fibers and a layer ofhigh impact resistant polymer pad which is impact resistant anddissipates impact force throughout the polymer pad, the said polymer padbeing interior of the said fabric layer with respect to the chest of theplayer.
 2. A chest protector as in claim 1, wherein the penetrationresistant woven fabric layer is a fabric of para-aramid fibers.
 3. Achest protector as in claim 1, wherein the chest protector plate hasinner-most and outer-most layers of plastic sheets selected from thegroup of low density polyethelene, polypropylene and ABS.
 4. A chestprotector as in claim 3, wherein the inner-most and outer-most layersare molded together to form an air tight pocket enclosing the otherlayers.
 5. A chest protector as in claim 1, wherein the polymer pad is adry polyurethane gel
 6. A chest protector as in claim 1, wherein theprotector plate includes another layer of a penetration resistant wovenfabric of high tensile strength fibers; the polymer pad being sandwichedbetween the two layers of penetration resistant woven fabric.
 7. A chestprotector as in claim 1, wherein the shirt is a two way stretch fabricincluding elastic fibers and having moisture wicking properties.
 8. Achest protector, as in claim 1, wherein, the shirt includespolypropylene fibers.
 9. A chest protector as in claim 1, wherein, thepocket and the protector plate extend across the width of the shirt'sfront area.
 10. A chest protector as in claim 1, wherein the protectorplate has curved side flanges, as seen from above, when worn by theplayer.
 11. A chest protector as in claim 6 wherein the additional layerof penetration resistant woven fabric is a fabric of para-aramid fibers.12. A chest protector as in claim 1, wherein as seen from above, whenworn by the player, the protector plate has a bowed-outward centersection and opposite curved side flanges.
 13. A chest protector as inclaim 1, wherein the penetration resistant woven fabric is a cross-wovenfabric selected from the group of para-aramid fibers, carbon fibers, andpara-aramid fibers combined with carbon fibers.
 14. A chest protector asin claim 1, wherein the polymer pad is a viscoelectric dry polymer. 15.A chest protector in sports medicine to protect a player against injuryfrom high speed projectile, such as balls and pucks, the chest protectorcomprising: a shirt adapted to be worn by the player with the shirthaving a front chest area, a pocket formed on the shirt, and extendingsufficiently across the width of the shirt front area to cover the heartof the player; a chest protector plate within the pocket, the chestprotector plate being an assembly of the following layers, in the ordernamed, starting with the outer-most layer with respect to the player'schest: a. the first layer is a moldable sheet of polyethylene plastic,b. the second layer is a layer of penetration resistant woven fabric ofhigh tensile strength fibers, c. the third layer is a high impactpolymer pad, which is impact resistant and dissipates impact forcethroughout the polymer pad, d. the fourth layer is a layer ofpenetration resistant woven fabric of high tensile strength fibers, ande. the fifth layer is a moldable sheet of polyethylene plastic.
 16. Achest protector as in claim 15, wherein the second and fourth layers area fabric of para-aramid fibers.
 17. A chest protector as in claim 15,wherein the first and fifth layers are molded together to form anair-tight pocket, enclosing the second and third layers.
 18. A chestprotector as in claim 15, wherein the polymer pad is a dry polyurethanegel.
 19. A chest protector as in claim 15, wherein the shirt is a twoway stretch fabric including elastic fibers and having moisture wickingproperties.
 20. A chest protector, as in claim 15, wherein the shirtincludes polypropylene fibers.
 21. A chest protector as in claim 15,wherein the pocket and the protector plate extend across the width ofthe shirt's front area.
 22. A chest protector as in claim 15, whereinthe protector plate has curved side flanges, as seen from above whenworn by the player.